In situ fabrication of type-II BiOIO3/Bi-MOF heterostructures with enhanced photocatalytic activity

BiOIO3/Bi-MOF (BF-x) composites with a porous hierarchical rod-like structure are prepared by in situ growth of BiOIO3 on Bi-MOF rod-like template. BiOIO3/Bi-MOF exhibit enhanced adsorption and photodegradation efficiency of RhB and TC. Within 60 min irradiation of Xe light, the optimal BF-40 composite can degrade 99% of RhB and 78% of TC, and the apparent rate constant k for photodegrading RhB (TC) is approximately 8.1 (3.9) and 29.6 (12.8) times higher than that of BiOIO3 and Bi-MOF, respectively. The BiOIO3/Bi-MOF heterojunction has larger specific surface area, improved light-harvesting ability and boosted separation and transfer efficiency of photocarrier, which benefit to enhance the photocatalytic activity of BiOIO3/Bi-MOF heterojunction. According to the semiconductor band structure theory and the results of radicals quenching experiment, the photocarriers at the interface of BiOIO3/Bi-MOF heterojunction follow the traditional type-II migration path, and a possible type-II photocatalytic degradation mechanism is proposed. This work provides more perspective in the development of in situ growth of 2D materials on MOF with the same metal element for water treatment and other potential applications.